keel over

/kil ˌoʊvər/

Other forms: keeled over; keeling over; keels over

To keel over is to collapse or topple over. If your rowboat hits a sharp rock, it may spring a leak, keel over, and sink.

When a boat keels over, It tips and starts to take on water — it capsizes. When a lamp or a llama keels over, it falls abruptly: "Stay away from the statues at the museum; things seem to keel over whenever you're near them." And if a person keels over, they slump to the ground, pass out, or collapse: "Once one blood donor fainted, the others started to keel over too." The nautical meaning came first, in the nineteenth century.

Definitions of keel over

1. verb

   turn over and fall
   type of:

   topple, tumble

   fall down, as if collapsing